1. Field of the Invention
The present invention relates to a caffeic acid derivative and a composition containing the same, more particularly, relates to a new caffeic acid derivative capable of stabilizing a vitamin C, which is unstable in the water, effectively and having antioxidant power and a composition containing the same.
2. Description of the Related Art
Generally, because a vitamin C has powerful effect in restraining or improving of aging phenomenon for example wrinkle, decrease of elasticity, drying, hyperpigmentation, etc through variable physiological functions in a living body, it has long been applied to groceries, medicine, cosmetics, etc.
Especially, because a vitamin C deoxidizes a oxidized melanin to restrain unnecessary biosynthesis of the melanin by acting itself as a contestant which attempts to combine with the tyrosine competitively against the tyrosinaze which is a kind of the ferment of the rate-governed process of the melanin biosynthesis process, and by acting itself as a restrainer which restrains revelation of tyrosinaze, it shows general activity over a physiological process related skin whitening. (Postaire E. et al., Biochem. Mol. Int., 42:1023-1033 (1997))
Further, the vitamin C relates to a biosynthesis of collagen which is most relative to skin wrinkle. Proline and rycin, which are substituted by the hydroxyl group, are necessary in the biosynthesis of the collagen of the skin. And derivation of the hydroxyl group of the two amino acids is the vitamin C in the cell. That is, synthesis of the collagen can be processed smoothly when the hydroxyl group of vitamin C is transferred to the two amino acids. Thus, existence of the vitamin C is necessary to the biosynthesis of collagen. (Padh H., Nutrition Reviews, 49:65-70 (1991)
Actually, the content of vitamin C in the skin decreases as growing older. It is known that wrinkle increases due to the elasticity decrease of the collagen and decrease of synthesis of a new collagen. Accordingly, it is reported that maintenance of the content of the vitamin C is one of most effective ways to delay the process of the skin aging. (Kevin J. Lenton et al., Am. J. Clin. Nutrl, 71:1194-1200 (2000))
Although the vitamin C has variable effects as described above, it is very unstable against heat, light, oxygen, water, etc. Accordingly, there are serious problems in the stability of the vitamin C because its titer decreases and its color/smell changes when it is exposed in the air or when it is oxidized in the water solution especially. Various vitamin C derivatives to solve this instability have been studied and used but there is a problem that those derivatives are inferior in effectiveness to the pure vitamin C.
Accordingly, study for the formulation to stabilize the vitamin C has taken placed in various ways. For example, it has been tried to make chemical assembly with gluconic acid or urocanic acid or to impregnate into cyclodextrin, giolite, liposome, etc, physically. As another way, method to coat vitamin C also has been presented.
However, those ways described above does not show satisfactory stability in effectiveness and further some of them are not adaptable for the formulation of cosmetics. Further, a study to stabilize the vitamin C by applying various antioxidant agents including vitamin E has been tried but change of color/smell cannot be solved. (U.S. Pat. No. 4,938,969)